[7768b8d] | 1 | // |
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| 2 | // Cforall Version 1.0.0 Copyright (C) 2019 University of Waterloo |
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| 3 | // |
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| 4 | // The contents of this file are covered under the licence agreement in the |
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| 5 | // file "LICENCE" distributed with Cforall. |
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| 6 | // |
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| 7 | // ready_queue.cfa -- |
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| 8 | // |
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| 9 | // Author : Thierry Delisle |
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| 10 | // Created On : Mon Nov dd 16:29:18 2019 |
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| 11 | // Last Modified By : |
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| 12 | // Last Modified On : |
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| 13 | // Update Count : |
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| 14 | // |
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| 15 | |
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| 16 | #define __cforall_thread__ |
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[1b143de] | 17 | // #define __CFA_DEBUG_PRINT_READY_QUEUE__ |
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[7768b8d] | 18 | |
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| 19 | #include "bits/defs.hfa" |
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| 20 | #include "kernel_private.hfa" |
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| 21 | |
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| 22 | #define _GNU_SOURCE |
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| 23 | #include "stdlib.hfa" |
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[61d7bec] | 24 | #include "math.hfa" |
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[7768b8d] | 25 | |
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[04b5cef] | 26 | #include <unistd.h> |
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| 27 | |
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[13c5e19] | 28 | #include "snzi.hfa" |
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| 29 | #include "ready_subqueue.hfa" |
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| 30 | |
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[7768b8d] | 31 | static const size_t cache_line_size = 64; |
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| 32 | |
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[dca5802] | 33 | // No overriden function, no environment variable, no define |
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| 34 | // fall back to a magic number |
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| 35 | #ifndef __CFA_MAX_PROCESSORS__ |
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[b388ee81] | 36 | #define __CFA_MAX_PROCESSORS__ 1024 |
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[dca5802] | 37 | #endif |
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[7768b8d] | 38 | |
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[d72c074] | 39 | #define BIAS 64 |
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[04b5cef] | 40 | |
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[dca5802] | 41 | // returns the maximum number of processors the RWLock support |
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[7768b8d] | 42 | __attribute__((weak)) unsigned __max_processors() { |
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| 43 | const char * max_cores_s = getenv("CFA_MAX_PROCESSORS"); |
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| 44 | if(!max_cores_s) { |
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[504a7dc] | 45 | __cfadbg_print_nolock(ready_queue, "No CFA_MAX_PROCESSORS in ENV\n"); |
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[dca5802] | 46 | return __CFA_MAX_PROCESSORS__; |
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[7768b8d] | 47 | } |
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| 48 | |
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| 49 | char * endptr = 0p; |
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| 50 | long int max_cores_l = strtol(max_cores_s, &endptr, 10); |
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| 51 | if(max_cores_l < 1 || max_cores_l > 65535) { |
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[504a7dc] | 52 | __cfadbg_print_nolock(ready_queue, "CFA_MAX_PROCESSORS out of range : %ld\n", max_cores_l); |
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[dca5802] | 53 | return __CFA_MAX_PROCESSORS__; |
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[7768b8d] | 54 | } |
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| 55 | if('\0' != *endptr) { |
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[504a7dc] | 56 | __cfadbg_print_nolock(ready_queue, "CFA_MAX_PROCESSORS not a decimal number : %s\n", max_cores_s); |
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[dca5802] | 57 | return __CFA_MAX_PROCESSORS__; |
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[7768b8d] | 58 | } |
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| 59 | |
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| 60 | return max_cores_l; |
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| 61 | } |
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| 62 | |
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| 63 | //======================================================================= |
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| 64 | // Cluster wide reader-writer lock |
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| 65 | //======================================================================= |
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[b388ee81] | 66 | void ?{}(__scheduler_RWLock_t & this) { |
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[7768b8d] | 67 | this.max = __max_processors(); |
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| 68 | this.alloc = 0; |
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| 69 | this.ready = 0; |
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| 70 | this.lock = false; |
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| 71 | this.data = alloc(this.max); |
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| 72 | |
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| 73 | /*paranoid*/ verify( 0 == (((uintptr_t)(this.data )) % 64) ); |
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| 74 | /*paranoid*/ verify( 0 == (((uintptr_t)(this.data + 1)) % 64) ); |
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| 75 | /*paranoid*/ verify(__atomic_is_lock_free(sizeof(this.alloc), &this.alloc)); |
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| 76 | /*paranoid*/ verify(__atomic_is_lock_free(sizeof(this.ready), &this.ready)); |
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| 77 | |
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| 78 | } |
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[b388ee81] | 79 | void ^?{}(__scheduler_RWLock_t & this) { |
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[7768b8d] | 80 | free(this.data); |
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| 81 | } |
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| 82 | |
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[9b1dcc2] | 83 | void ?{}( __scheduler_lock_id_t & this, __processor_id_t * proc ) { |
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[7768b8d] | 84 | this.handle = proc; |
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| 85 | this.lock = false; |
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[64a7146] | 86 | #ifdef __CFA_WITH_VERIFY__ |
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| 87 | this.owned = false; |
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| 88 | #endif |
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[7768b8d] | 89 | } |
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| 90 | |
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| 91 | //======================================================================= |
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| 92 | // Lock-Free registering/unregistering of threads |
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[9b1dcc2] | 93 | unsigned doregister( struct __processor_id_t * proc ) with(*__scheduler_lock) { |
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[b388ee81] | 94 | __cfadbg_print_safe(ready_queue, "Kernel : Registering proc %p for RW-Lock\n", proc); |
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[504a7dc] | 95 | |
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[7768b8d] | 96 | // Step - 1 : check if there is already space in the data |
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| 97 | uint_fast32_t s = ready; |
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| 98 | |
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| 99 | // Check among all the ready |
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| 100 | for(uint_fast32_t i = 0; i < s; i++) { |
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[9b1dcc2] | 101 | __processor_id_t * null = 0p; // Re-write every loop since compare thrashes it |
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[7768b8d] | 102 | if( __atomic_load_n(&data[i].handle, (int)__ATOMIC_RELAXED) == null |
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| 103 | && __atomic_compare_exchange_n( &data[i].handle, &null, proc, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) { |
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| 104 | /*paranoid*/ verify(i < ready); |
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[64a7146] | 105 | /*paranoid*/ verify(0 == (__alignof__(data[i]) % cache_line_size)); |
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[7768b8d] | 106 | /*paranoid*/ verify((((uintptr_t)&data[i]) % cache_line_size) == 0); |
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| 107 | return i; |
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| 108 | } |
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| 109 | } |
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| 110 | |
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[b388ee81] | 111 | if(max <= alloc) abort("Trying to create more than %ud processors", __scheduler_lock->max); |
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[7768b8d] | 112 | |
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| 113 | // Step - 2 : F&A to get a new spot in the array. |
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| 114 | uint_fast32_t n = __atomic_fetch_add(&alloc, 1, __ATOMIC_SEQ_CST); |
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[b388ee81] | 115 | if(max <= n) abort("Trying to create more than %ud processors", __scheduler_lock->max); |
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[7768b8d] | 116 | |
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| 117 | // Step - 3 : Mark space as used and then publish it. |
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[9b1dcc2] | 118 | __scheduler_lock_id_t * storage = (__scheduler_lock_id_t *)&data[n]; |
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[7768b8d] | 119 | (*storage){ proc }; |
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| 120 | while(true) { |
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| 121 | unsigned copy = n; |
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| 122 | if( __atomic_load_n(&ready, __ATOMIC_RELAXED) == n |
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| 123 | && __atomic_compare_exchange_n(&ready, ©, n + 1, true, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)) |
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| 124 | break; |
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| 125 | asm volatile("pause"); |
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| 126 | } |
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| 127 | |
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[1b143de] | 128 | __cfadbg_print_safe(ready_queue, "Kernel : Registering proc %p done, id %lu\n", proc, n); |
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[504a7dc] | 129 | |
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[7768b8d] | 130 | // Return new spot. |
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| 131 | /*paranoid*/ verify(n < ready); |
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[37ba662] | 132 | /*paranoid*/ verify(__alignof__(data[n]) == (2 * cache_line_size)); |
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[7768b8d] | 133 | /*paranoid*/ verify((((uintptr_t)&data[n]) % cache_line_size) == 0); |
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| 134 | return n; |
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| 135 | } |
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| 136 | |
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[9b1dcc2] | 137 | void unregister( struct __processor_id_t * proc ) with(*__scheduler_lock) { |
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[7768b8d] | 138 | unsigned id = proc->id; |
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| 139 | /*paranoid*/ verify(id < ready); |
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| 140 | /*paranoid*/ verify(proc == __atomic_load_n(&data[id].handle, __ATOMIC_RELAXED)); |
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| 141 | __atomic_store_n(&data[id].handle, 0p, __ATOMIC_RELEASE); |
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[504a7dc] | 142 | |
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| 143 | __cfadbg_print_safe(ready_queue, "Kernel : Unregister proc %p\n", proc); |
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[7768b8d] | 144 | } |
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| 145 | |
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| 146 | //----------------------------------------------------------------------- |
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| 147 | // Writer side : acquire when changing the ready queue, e.g. adding more |
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| 148 | // queues or removing them. |
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[b388ee81] | 149 | uint_fast32_t ready_mutate_lock( void ) with(*__scheduler_lock) { |
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[7768b8d] | 150 | // Step 1 : lock global lock |
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| 151 | // It is needed to avoid processors that register mid Critical-Section |
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| 152 | // to simply lock their own lock and enter. |
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| 153 | __atomic_acquire( &lock ); |
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| 154 | |
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| 155 | // Step 2 : lock per-proc lock |
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| 156 | // Processors that are currently being registered aren't counted |
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| 157 | // but can't be in read_lock or in the critical section. |
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| 158 | // All other processors are counted |
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| 159 | uint_fast32_t s = ready; |
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| 160 | for(uint_fast32_t i = 0; i < s; i++) { |
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| 161 | __atomic_acquire( &data[i].lock ); |
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| 162 | } |
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| 163 | |
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| 164 | return s; |
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| 165 | } |
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| 166 | |
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[b388ee81] | 167 | void ready_mutate_unlock( uint_fast32_t last_s ) with(*__scheduler_lock) { |
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[7768b8d] | 168 | // Step 1 : release local locks |
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| 169 | // This must be done while the global lock is held to avoid |
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| 170 | // threads that where created mid critical section |
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| 171 | // to race to lock their local locks and have the writer |
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| 172 | // immidiately unlock them |
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| 173 | // Alternative solution : return s in write_lock and pass it to write_unlock |
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| 174 | for(uint_fast32_t i = 0; i < last_s; i++) { |
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| 175 | verify(data[i].lock); |
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| 176 | __atomic_store_n(&data[i].lock, (bool)false, __ATOMIC_RELEASE); |
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| 177 | } |
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| 178 | |
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| 179 | // Step 2 : release global lock |
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| 180 | /*paranoid*/ assert(true == lock); |
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| 181 | __atomic_store_n(&lock, (bool)false, __ATOMIC_RELEASE); |
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| 182 | } |
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| 183 | |
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| 184 | //======================================================================= |
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[13c5e19] | 185 | // Cforall Reqdy Queue used for scheduling |
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[b798713] | 186 | //======================================================================= |
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| 187 | void ?{}(__ready_queue_t & this) with (this) { |
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| 188 | |
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[dca5802] | 189 | lanes.data = alloc(4); |
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[b798713] | 190 | for( i; 4 ) { |
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[dca5802] | 191 | (lanes.data[i]){}; |
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[b798713] | 192 | } |
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[dca5802] | 193 | lanes.count = 4; |
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[61d7bec] | 194 | snzi{ log2( lanes.count / 8 ) }; |
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[b798713] | 195 | } |
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| 196 | |
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| 197 | void ^?{}(__ready_queue_t & this) with (this) { |
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[dca5802] | 198 | verify( 4 == lanes.count ); |
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[61d7bec] | 199 | verify( !query( snzi ) ); |
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| 200 | |
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| 201 | ^(snzi){}; |
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[b798713] | 202 | |
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| 203 | for( i; 4 ) { |
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[dca5802] | 204 | ^(lanes.data[i]){}; |
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[b798713] | 205 | } |
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[dca5802] | 206 | free(lanes.data); |
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| 207 | } |
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| 208 | |
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[64a7146] | 209 | //----------------------------------------------------------------------- |
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| 210 | __attribute__((hot)) bool query(struct cluster * cltr) { |
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| 211 | return query(cltr->ready_queue.snzi); |
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| 212 | } |
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| 213 | |
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[dca5802] | 214 | //----------------------------------------------------------------------- |
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[504a7dc] | 215 | __attribute__((hot)) bool push(struct cluster * cltr, struct $thread * thrd) with (cltr->ready_queue) { |
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[61d7bec] | 216 | __cfadbg_print_safe(ready_queue, "Kernel : Pushing %p on cluster %p\n", thrd, cltr); |
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[1b143de] | 217 | |
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[dca5802] | 218 | // write timestamp |
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[b798713] | 219 | thrd->link.ts = rdtscl(); |
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| 220 | |
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[52769ba] | 221 | #if defined(BIAS) && !defined(__CFA_NO_STATISTICS__) |
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| 222 | bool local = false; |
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[d72c074] | 223 | int preferred = |
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| 224 | //* |
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| 225 | kernelTLS.this_processor ? kernelTLS.this_processor->id * 4 : -1; |
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| 226 | /*/ |
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| 227 | thrd->link.preferred * 4; |
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| 228 | //*/ |
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| 229 | |
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| 230 | |
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[52769ba] | 231 | #endif |
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| 232 | |
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[dca5802] | 233 | // Try to pick a lane and lock it |
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| 234 | unsigned i; |
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| 235 | do { |
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| 236 | // Pick the index of a lane |
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[04b5cef] | 237 | #if defined(BIAS) |
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| 238 | unsigned r = __tls_rand(); |
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| 239 | unsigned rlow = r % BIAS; |
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| 240 | unsigned rhigh = r / BIAS; |
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[d72c074] | 241 | if((0 != rlow) && preferred >= 0) { |
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[04b5cef] | 242 | // (BIAS - 1) out of BIAS chances |
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| 243 | // Use perferred queues |
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[d72c074] | 244 | i = preferred + (rhigh % 4); |
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[13c5e19] | 245 | |
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| 246 | #if !defined(__CFA_NO_STATISTICS__) |
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[52769ba] | 247 | local = true; |
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[13c5e19] | 248 | __tls_stats()->ready.pick.push.local++; |
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| 249 | #endif |
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[04b5cef] | 250 | } |
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| 251 | else { |
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| 252 | // 1 out of BIAS chances |
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| 253 | // Use all queues |
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| 254 | i = rhigh; |
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[52769ba] | 255 | local = false; |
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[04b5cef] | 256 | } |
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| 257 | #else |
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| 258 | i = __tls_rand(); |
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| 259 | #endif |
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| 260 | |
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| 261 | i %= __atomic_load_n( &lanes.count, __ATOMIC_RELAXED ); |
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[b798713] | 262 | |
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| 263 | #if !defined(__CFA_NO_STATISTICS__) |
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[8834751] | 264 | __tls_stats()->ready.pick.push.attempt++; |
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[b798713] | 265 | #endif |
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| 266 | |
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| 267 | // If we can't lock it retry |
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[dca5802] | 268 | } while( !__atomic_try_acquire( &lanes.data[i].lock ) ); |
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[b798713] | 269 | |
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[dca5802] | 270 | bool first = false; |
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| 271 | |
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| 272 | // Actually push it |
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| 273 | bool lane_first = push(lanes.data[i], thrd); |
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| 274 | |
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| 275 | // If this lane used to be empty we need to do more |
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| 276 | if(lane_first) { |
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[504a7dc] | 277 | // Check if the entire queue used to be empty |
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[61d7bec] | 278 | first = !query(snzi); |
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| 279 | |
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| 280 | // Update the snzi |
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| 281 | arrive( snzi, i ); |
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[b798713] | 282 | } |
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[dca5802] | 283 | |
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| 284 | // Unlock and return |
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| 285 | __atomic_unlock( &lanes.data[i].lock ); |
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| 286 | |
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[1b143de] | 287 | __cfadbg_print_safe(ready_queue, "Kernel : Pushed %p on cluster %p (idx: %u, mask %llu, first %d)\n", thrd, cltr, i, used.mask[0], lane_first); |
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| 288 | |
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[dca5802] | 289 | // Update statistics |
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| 290 | #if !defined(__CFA_NO_STATISTICS__) |
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[52769ba] | 291 | #if defined(BIAS) |
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| 292 | if( local ) __tls_stats()->ready.pick.push.lsuccess++; |
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| 293 | #endif |
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[8834751] | 294 | __tls_stats()->ready.pick.push.success++; |
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[dca5802] | 295 | #endif |
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| 296 | |
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| 297 | // return whether or not the list was empty before this push |
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| 298 | return first; |
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[b798713] | 299 | } |
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| 300 | |
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[13c5e19] | 301 | static struct $thread * try_pop(struct cluster * cltr, unsigned i, unsigned j); |
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| 302 | static struct $thread * try_pop(struct cluster * cltr, unsigned i); |
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| 303 | |
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| 304 | // Pop from the ready queue from a given cluster |
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| 305 | __attribute__((hot)) $thread * pop(struct cluster * cltr) with (cltr->ready_queue) { |
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| 306 | /* paranoid */ verify( lanes.count > 0 ); |
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| 307 | #if defined(BIAS) |
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| 308 | // Don't bother trying locally too much |
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| 309 | int local_tries = 8; |
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| 310 | #endif |
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| 311 | |
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| 312 | // As long as the list is not empty, try finding a lane that isn't empty and pop from it |
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| 313 | while( query(snzi) ) { |
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| 314 | // Pick two lists at random |
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| 315 | unsigned i,j; |
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| 316 | #if defined(BIAS) |
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[52769ba] | 317 | #if !defined(__CFA_NO_STATISTICS__) |
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| 318 | bool local = false; |
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| 319 | #endif |
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[13c5e19] | 320 | uint64_t r = __tls_rand(); |
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| 321 | unsigned rlow = r % BIAS; |
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| 322 | uint64_t rhigh = r / BIAS; |
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| 323 | if(local_tries && 0 != rlow) { |
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| 324 | // (BIAS - 1) out of BIAS chances |
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| 325 | // Use perferred queues |
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| 326 | unsigned pid = kernelTLS.this_processor->id * 4; |
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| 327 | i = pid + (rhigh % 4); |
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| 328 | j = pid + ((rhigh >> 32ull) % 4); |
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| 329 | |
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| 330 | // count the tries |
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| 331 | local_tries--; |
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| 332 | |
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| 333 | #if !defined(__CFA_NO_STATISTICS__) |
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[52769ba] | 334 | local = true; |
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[13c5e19] | 335 | __tls_stats()->ready.pick.pop.local++; |
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| 336 | #endif |
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| 337 | } |
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| 338 | else { |
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| 339 | // 1 out of BIAS chances |
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| 340 | // Use all queues |
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| 341 | i = rhigh; |
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| 342 | j = rhigh >> 32ull; |
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| 343 | } |
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| 344 | #else |
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| 345 | i = __tls_rand(); |
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| 346 | j = __tls_rand(); |
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| 347 | #endif |
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| 348 | |
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| 349 | i %= __atomic_load_n( &lanes.count, __ATOMIC_RELAXED ); |
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| 350 | j %= __atomic_load_n( &lanes.count, __ATOMIC_RELAXED ); |
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| 351 | |
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| 352 | // try popping from the 2 picked lists |
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| 353 | struct $thread * thrd = try_pop(cltr, i, j); |
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[52769ba] | 354 | if(thrd) { |
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| 355 | #if defined(BIAS) && !defined(__CFA_NO_STATISTICS__) |
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| 356 | if( local ) __tls_stats()->ready.pick.pop.lsuccess++; |
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| 357 | #endif |
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| 358 | return thrd; |
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| 359 | } |
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[13c5e19] | 360 | } |
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| 361 | |
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| 362 | // All lanes where empty return 0p |
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| 363 | return 0p; |
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| 364 | } |
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| 365 | |
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[b798713] | 366 | //----------------------------------------------------------------------- |
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[dca5802] | 367 | // Given 2 indexes, pick the list with the oldest push an try to pop from it |
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[13c5e19] | 368 | static inline struct $thread * try_pop(struct cluster * cltr, unsigned i, unsigned j) with (cltr->ready_queue) { |
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[b798713] | 369 | #if !defined(__CFA_NO_STATISTICS__) |
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[8834751] | 370 | __tls_stats()->ready.pick.pop.attempt++; |
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[b798713] | 371 | #endif |
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| 372 | |
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| 373 | // Pick the bet list |
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| 374 | int w = i; |
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[dca5802] | 375 | if( __builtin_expect(!is_empty(lanes.data[j]), true) ) { |
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| 376 | w = (ts(lanes.data[i]) < ts(lanes.data[j])) ? i : j; |
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[b798713] | 377 | } |
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| 378 | |
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[13c5e19] | 379 | return try_pop(cltr, w); |
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| 380 | } |
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| 381 | |
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| 382 | static inline struct $thread * try_pop(struct cluster * cltr, unsigned w) with (cltr->ready_queue) { |
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[dca5802] | 383 | // Get relevant elements locally |
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| 384 | __intrusive_lane_t & lane = lanes.data[w]; |
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| 385 | |
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[b798713] | 386 | // If list looks empty retry |
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[dca5802] | 387 | if( is_empty(lane) ) return 0p; |
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[b798713] | 388 | |
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| 389 | // If we can't get the lock retry |
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[dca5802] | 390 | if( !__atomic_try_acquire(&lane.lock) ) return 0p; |
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[b798713] | 391 | |
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| 392 | |
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| 393 | // If list is empty, unlock and retry |
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[dca5802] | 394 | if( is_empty(lane) ) { |
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| 395 | __atomic_unlock(&lane.lock); |
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[b798713] | 396 | return 0p; |
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| 397 | } |
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| 398 | |
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| 399 | // Actually pop the list |
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[504a7dc] | 400 | struct $thread * thrd; |
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[b798713] | 401 | bool emptied; |
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[dca5802] | 402 | [thrd, emptied] = pop(lane); |
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[b798713] | 403 | |
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[dca5802] | 404 | /* paranoid */ verify(thrd); |
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| 405 | /* paranoid */ verify(lane.lock); |
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[b798713] | 406 | |
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[dca5802] | 407 | // If this was the last element in the lane |
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[b798713] | 408 | if(emptied) { |
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[61d7bec] | 409 | depart( snzi, w ); |
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[b798713] | 410 | } |
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| 411 | |
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| 412 | // Unlock and return |
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[dca5802] | 413 | __atomic_unlock(&lane.lock); |
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[b798713] | 414 | |
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[dca5802] | 415 | // Update statistics |
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[b798713] | 416 | #if !defined(__CFA_NO_STATISTICS__) |
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[8834751] | 417 | __tls_stats()->ready.pick.pop.success++; |
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[b798713] | 418 | #endif |
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| 419 | |
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[d72c074] | 420 | // Update the thread bias |
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| 421 | thrd->link.preferred = w / 4; |
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| 422 | |
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[dca5802] | 423 | // return the popped thread |
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[b798713] | 424 | return thrd; |
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| 425 | } |
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[13c5e19] | 426 | //----------------------------------------------------------------------- |
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[b798713] | 427 | |
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[13c5e19] | 428 | bool remove_head(struct cluster * cltr, struct $thread * thrd) with (cltr->ready_queue) { |
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| 429 | for(i; lanes.count) { |
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| 430 | __intrusive_lane_t & lane = lanes.data[i]; |
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[b798713] | 431 | |
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[13c5e19] | 432 | bool removed = false; |
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[04b5cef] | 433 | |
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[13c5e19] | 434 | __atomic_acquire(&lane.lock); |
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| 435 | if(head(lane)->link.next == thrd) { |
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| 436 | $thread * pthrd; |
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| 437 | bool emptied; |
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| 438 | [pthrd, emptied] = pop(lane); |
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[04b5cef] | 439 | |
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[13c5e19] | 440 | /* paranoid */ verify( pthrd == thrd ); |
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[61d7bec] | 441 | |
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[13c5e19] | 442 | removed = true; |
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| 443 | if(emptied) { |
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| 444 | depart( snzi, i ); |
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| 445 | } |
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| 446 | } |
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| 447 | __atomic_unlock(&lane.lock); |
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[b798713] | 448 | |
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[13c5e19] | 449 | if( removed ) return true; |
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| 450 | } |
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| 451 | return false; |
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[b798713] | 452 | } |
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| 453 | |
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| 454 | //----------------------------------------------------------------------- |
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| 455 | |
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| 456 | static void check( __ready_queue_t & q ) with (q) { |
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| 457 | #if defined(__CFA_WITH_VERIFY__) |
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| 458 | { |
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[dca5802] | 459 | for( idx ; lanes.count ) { |
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| 460 | __intrusive_lane_t & sl = lanes.data[idx]; |
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| 461 | assert(!lanes.data[idx].lock); |
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[b798713] | 462 | |
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| 463 | assert(head(sl)->link.prev == 0p ); |
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| 464 | assert(head(sl)->link.next->link.prev == head(sl) ); |
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| 465 | assert(tail(sl)->link.next == 0p ); |
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| 466 | assert(tail(sl)->link.prev->link.next == tail(sl) ); |
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| 467 | |
---|
| 468 | if(sl.before.link.ts == 0l) { |
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| 469 | assert(tail(sl)->link.prev == head(sl)); |
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| 470 | assert(head(sl)->link.next == tail(sl)); |
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[1b143de] | 471 | } else { |
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| 472 | assert(tail(sl)->link.prev != head(sl)); |
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| 473 | assert(head(sl)->link.next != tail(sl)); |
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[b798713] | 474 | } |
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| 475 | } |
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| 476 | } |
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| 477 | #endif |
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| 478 | } |
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| 479 | |
---|
| 480 | // Call this function of the intrusive list was moved using memcpy |
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[dca5802] | 481 | // fixes the list so that the pointers back to anchors aren't left dangling |
---|
| 482 | static inline void fix(__intrusive_lane_t & ll) { |
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| 483 | // if the list is not empty then follow he pointer and fix its reverse |
---|
| 484 | if(!is_empty(ll)) { |
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[b798713] | 485 | head(ll)->link.next->link.prev = head(ll); |
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| 486 | tail(ll)->link.prev->link.next = tail(ll); |
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| 487 | } |
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| 488 | // Otherwise just reset the list |
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| 489 | else { |
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[dca5802] | 490 | verify(tail(ll)->link.next == 0p); |
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[b798713] | 491 | tail(ll)->link.prev = head(ll); |
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| 492 | head(ll)->link.next = tail(ll); |
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[dca5802] | 493 | verify(head(ll)->link.prev == 0p); |
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[b798713] | 494 | } |
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| 495 | } |
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| 496 | |
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[dca5802] | 497 | // Grow the ready queue |
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[b798713] | 498 | void ready_queue_grow (struct cluster * cltr) { |
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[64a7146] | 499 | /* paranoid */ verify( ready_mutate_islocked() ); |
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[504a7dc] | 500 | __cfadbg_print_safe(ready_queue, "Kernel : Growing ready queue\n"); |
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[b798713] | 501 | |
---|
[dca5802] | 502 | // Make sure that everything is consistent |
---|
| 503 | /* paranoid */ check( cltr->ready_queue ); |
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| 504 | |
---|
| 505 | // grow the ready queue |
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[b798713] | 506 | with( cltr->ready_queue ) { |
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[61d7bec] | 507 | ^(snzi){}; |
---|
[b798713] | 508 | |
---|
[61d7bec] | 509 | size_t ncount = lanes.count; |
---|
[b798713] | 510 | |
---|
[dca5802] | 511 | // increase count |
---|
[b798713] | 512 | ncount += 4; |
---|
| 513 | |
---|
[dca5802] | 514 | // Allocate new array (uses realloc and memcpies the data) |
---|
| 515 | lanes.data = alloc(lanes.data, ncount); |
---|
[b798713] | 516 | |
---|
| 517 | // Fix the moved data |
---|
[dca5802] | 518 | for( idx; (size_t)lanes.count ) { |
---|
| 519 | fix(lanes.data[idx]); |
---|
[b798713] | 520 | } |
---|
| 521 | |
---|
| 522 | // Construct new data |
---|
[dca5802] | 523 | for( idx; (size_t)lanes.count ~ ncount) { |
---|
| 524 | (lanes.data[idx]){}; |
---|
[b798713] | 525 | } |
---|
| 526 | |
---|
| 527 | // Update original |
---|
[dca5802] | 528 | lanes.count = ncount; |
---|
| 529 | |
---|
[61d7bec] | 530 | // Re-create the snzi |
---|
| 531 | snzi{ log2( lanes.count / 8 ) }; |
---|
| 532 | for( idx; (size_t)lanes.count ) { |
---|
| 533 | if( !is_empty(lanes.data[idx]) ) { |
---|
| 534 | arrive(snzi, idx); |
---|
| 535 | } |
---|
| 536 | } |
---|
[b798713] | 537 | } |
---|
| 538 | |
---|
| 539 | // Make sure that everything is consistent |
---|
[dca5802] | 540 | /* paranoid */ check( cltr->ready_queue ); |
---|
| 541 | |
---|
[504a7dc] | 542 | __cfadbg_print_safe(ready_queue, "Kernel : Growing ready queue done\n"); |
---|
[dca5802] | 543 | |
---|
[64a7146] | 544 | /* paranoid */ verify( ready_mutate_islocked() ); |
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[b798713] | 545 | } |
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| 546 | |
---|
[dca5802] | 547 | // Shrink the ready queue |
---|
[b798713] | 548 | void ready_queue_shrink(struct cluster * cltr) { |
---|
[64a7146] | 549 | /* paranoid */ verify( ready_mutate_islocked() ); |
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[504a7dc] | 550 | __cfadbg_print_safe(ready_queue, "Kernel : Shrinking ready queue\n"); |
---|
[dca5802] | 551 | |
---|
| 552 | // Make sure that everything is consistent |
---|
| 553 | /* paranoid */ check( cltr->ready_queue ); |
---|
| 554 | |
---|
[b798713] | 555 | with( cltr->ready_queue ) { |
---|
[61d7bec] | 556 | ^(snzi){}; |
---|
| 557 | |
---|
[dca5802] | 558 | size_t ocount = lanes.count; |
---|
[b798713] | 559 | // Check that we have some space left |
---|
| 560 | if(ocount < 8) abort("Program attempted to destroy more Ready Queues than were created"); |
---|
| 561 | |
---|
[dca5802] | 562 | // reduce the actual count so push doesn't use the old queues |
---|
| 563 | lanes.count -= 4; |
---|
| 564 | verify(ocount > lanes.count); |
---|
| 565 | |
---|
| 566 | // for printing count the number of displaced threads |
---|
[504a7dc] | 567 | #if defined(__CFA_DEBUG_PRINT__) || defined(__CFA_DEBUG_PRINT_READY_QUEUE__) |
---|
[dca5802] | 568 | __attribute__((unused)) size_t displaced = 0; |
---|
| 569 | #endif |
---|
[b798713] | 570 | |
---|
| 571 | // redistribute old data |
---|
[dca5802] | 572 | for( idx; (size_t)lanes.count ~ ocount) { |
---|
| 573 | // Lock is not strictly needed but makes checking invariants much easier |
---|
[1b143de] | 574 | __attribute__((unused)) bool locked = __atomic_try_acquire(&lanes.data[idx].lock); |
---|
[b798713] | 575 | verify(locked); |
---|
[dca5802] | 576 | |
---|
| 577 | // As long as we can pop from this lane to push the threads somewhere else in the queue |
---|
| 578 | while(!is_empty(lanes.data[idx])) { |
---|
[504a7dc] | 579 | struct $thread * thrd; |
---|
[b798713] | 580 | __attribute__((unused)) bool _; |
---|
[dca5802] | 581 | [thrd, _] = pop(lanes.data[idx]); |
---|
| 582 | |
---|
[b798713] | 583 | push(cltr, thrd); |
---|
[dca5802] | 584 | |
---|
| 585 | // for printing count the number of displaced threads |
---|
[504a7dc] | 586 | #if defined(__CFA_DEBUG_PRINT__) || defined(__CFA_DEBUG_PRINT_READY_QUEUE__) |
---|
[dca5802] | 587 | displaced++; |
---|
| 588 | #endif |
---|
[b798713] | 589 | } |
---|
| 590 | |
---|
[dca5802] | 591 | // Unlock the lane |
---|
| 592 | __atomic_unlock(&lanes.data[idx].lock); |
---|
[b798713] | 593 | |
---|
| 594 | // TODO print the queue statistics here |
---|
| 595 | |
---|
[dca5802] | 596 | ^(lanes.data[idx]){}; |
---|
[b798713] | 597 | } |
---|
| 598 | |
---|
[504a7dc] | 599 | __cfadbg_print_safe(ready_queue, "Kernel : Shrinking ready queue displaced %zu threads\n", displaced); |
---|
[c84b4be] | 600 | |
---|
[dca5802] | 601 | // Allocate new array (uses realloc and memcpies the data) |
---|
| 602 | lanes.data = alloc(lanes.data, lanes.count); |
---|
[b798713] | 603 | |
---|
| 604 | // Fix the moved data |
---|
[dca5802] | 605 | for( idx; (size_t)lanes.count ) { |
---|
| 606 | fix(lanes.data[idx]); |
---|
[b798713] | 607 | } |
---|
[c84b4be] | 608 | |
---|
[61d7bec] | 609 | // Re-create the snzi |
---|
| 610 | snzi{ log2( lanes.count / 8 ) }; |
---|
| 611 | for( idx; (size_t)lanes.count ) { |
---|
| 612 | if( !is_empty(lanes.data[idx]) ) { |
---|
| 613 | arrive(snzi, idx); |
---|
| 614 | } |
---|
| 615 | } |
---|
[b798713] | 616 | } |
---|
| 617 | |
---|
| 618 | // Make sure that everything is consistent |
---|
[dca5802] | 619 | /* paranoid */ check( cltr->ready_queue ); |
---|
| 620 | |
---|
[504a7dc] | 621 | __cfadbg_print_safe(ready_queue, "Kernel : Shrinking ready queue done\n"); |
---|
[64a7146] | 622 | /* paranoid */ verify( ready_mutate_islocked() ); |
---|
[8834751] | 623 | } |
---|